This invention relates to self-referenced tracking.
Virtual reality (VR) systems require tracking of the orientation and position of a user's head and hands with respect to a world coordinate frame in order to control view parameters for head mounted devices (HMDs) and allow manual interactions with the virtual world. In laboratory VR setups, this tracking has been achieved with a variety of mechanical, acoustic, magnetic, and optical systems. These systems require propagation of a signal between a fixed “source” and the tracked “sensor” and therefore limit the range of operation. They also require a degree of care in setting up the source or preparing the site that reduces their utility for field use.
The emerging fields of wearable computing and augmented reality (AR) require tracking systems to be wearable and capable of operating essentially immediately in arbitrary environments. “Sourceless” orientation trackers have been developed based on geomagnetic and/or inertial sensors. They allow enough control to look around the virtual environment and fly through it, but they don't enable the “reach-out-and-grab” interactions that make virtual environments so intuitive and which are needed to facilitate computer interaction.